Discrepancy between inplace add and add for list and iterables

Documentation

Noticed this discrepancy between inplace add and add for list and iterables, not sure if this behavior is purposefully intended or a bug:

The Addition Assignment += operator will concatenate str to list, treating the str as an iterable and behaving like list.extend(...) instead of throwing TypeError, as one might expect, since the Addition operator + throws a TypeError when attempting to concatenate str to list.

未指定來源檔案或測試。首先重現所附範例，這些範例比較了字串和其他 iterable 的 list += 與 list +，然後閱讀 Python 語言文件中與這些運算子相關的內容。完成的標準是確立該差異的預期行為，並找出適當的文件修改或釐清之處。